I would switch between scenarios. (every significant milestone, or around three or four sessions, but mainly whenever the current "dungeon", "book", or "adventure" is done.) I'd suggest taking a look at the books in the series- there are one or two long term issues throughout the books, but by and large each one is a mystery within the book.
What you need to make sure of is that you finish each adventure before handing things over. The villain might not be dead, but he's beaten for now. The city might not be safe, but this particular threat won't be what kills it. (Note: If the bad guys won, which they do sometimes, then that's an ending too.) In the section on cities, it points out that city aspects are expected to change as the game progresses. Basically, whenever one of those aspects changes, and everyone involved in the hubbub has conceded that there's not much more they want to try, then you can safely change. There are a few possibly hiccups.
First, what was the odd character out doing? In Dresden, you all didn't just meet at a bar, so when bad stuff went down and you all pitched together, why did one of you not show up? (That would be the DMs character.) This isn't a hard problem, but you do need to think about it. Did the bad guys start out by neutralizing them? Are they busy dealing with another part of the problem? Are they recovering from a consequence from last scenario? Or, are they right there besides everyone else? (Some people can play a character and DM the game at the same time. It doesn't work very well for me, but if you can pull it off go for it.)
Second, are there any secrets? Is one the the players related to one of the bad guys? Is the big bad working to find the three pieces of the triforce, one each scenario? Are the bad guys secretly breaking the seventh law? Is one of the players secretly a red court infected? (That one actually came up- A player got infected during a session, and hid it effectively for two scenarios. Then we switched DMs when the DM went for a semester abroad, and I had to deal with this sudden new plot thread, and pretending I didn't know when the DM got back. If you're rotating DMs, everyone just has to be okay with the fact that inside of three or four rotations, everyone is going to know whatever deep dark secret they were hiding.)
The best way to fix this is to just not have secrets, but that takes some of the fun out of it. Depending on the players, they could roleplay not knowing. (I love doing that sometimes- the example in the book goes something like "A ghoul snuck in the back window. You failed the alertness roll, so why didn't you notice?") Thing is, just because you're not letting it get transferred to your character, doesn't mean that it's as fun. I love surprises and plot twists, and that is something that gets harder to do as more people share the DM seat. One way to still have this is to have a bunch of bad guys, each with their own separate plots, each run by a different DM. Then again, maybe the big reveal isn't as important.
Another way, if you're all clever at this sort of thing and everyone is cool with it, is to retcon a little when you need. Anything that happened, happened, but you might try something like "Okay, so the first time it turned out Jim Blackhat was a sorcerer. Then next time in turned out he was also a redcourt, but he had been trying to keep it a secret! But now, in his secret lair, you find the true source of his power- He's been breaking the seventh law!" Basically, add your own twist every time the DM seat changes hands. Just be careful this doesn't get too tangled and confusing, and remember not to change anything that actually verifiable happened. Blackhat fell off a cliff, but survived and is back for revenge is probably fine, we shot Blackhat in the chest at point blank but he was a vampire and regenerated might be, but around the time the players burn the body and douse the unmarked body in holy water, he does not come back. That's why evil villains have apprentices anyway!
Third, all characters get access to all milestones, even if they slept through the whole thing. That sounds a little obvious to some, and wrong and unfair to others, but especially if there are a couple of significant milestones or even one major milestone, you need to give it to all characters. Playing more than a few skillpoints behind, or even one refresh behind, is an irritating shift in power and agency. Your mileage may vary on that, but it's not hard to come up with a story to justify it if you need.
In the end, it works out pretty well. Just realize that you are giving up a certain level of genuine surprise and twist to the story, and the rotating cast will feel a little different than the same tight nit team every time.
From the writer, Fred Hicks:
biomancy is a tricky, poorly documented part of magic in the source
material. But, yes, it’d incorporate transformation magic, and its
healing elements likely manifest as accelerated medical care, only
occasionally branching into true “regeneration” type stuff at the
extremes.
With that in mind, I think that a Biomancer is more akin to a doctor than a cleric, which seems to fit the source material. Keep in mind, that this is an urban fantasy, so having an easy way to heal an extreme consequence (an arm being taken off, for instance) brings to mind the question of why is cancer still a problem, and (without going into too much detail) why are extreme wounds to characters in the source material such a problem.
That said, I'd look towards the character concept and the focus of the player in creating the character to how you might tailor things to make the concept work in your game, and make things satisfying to the player in combat.
In the Dresden Files combat, there are four basic conflict actions: Attack, Maneuver, Block, and Sprint. (ref YS199
). Taking sprint out of the equation and reducing the actions to their simplest intent, these actions are meant to either protect the character (thus prolonging the conflict), damage the opposition (thus contributing towards the end of the conflict), or set up opportunities for one or the other.
An application of Biomancy that would fit within these rules is a Block. If someone is in combat, the Biomancer could focus himself on increasing their natural resistance to damage and their natural recovery. The description of the effect would reinforce the use of Biomancy i.e. instead of a kinetic shield stopping the bullet or altering it's path, the bullet impacts the target, but the biomantic energies were able to knit the damaged body before the effects of the shock could even register.
If this is not enough to satisfy the concept and you want to extrapolate the rules and/or use the FATE SRD rules, you can move beyond this. An example of mitigation of consequences is already given- and I think given the statement above about what the intent of what biomancy would be fits their example. So I'd concentrate on stress.
Looking at YS201
, we see a definition for stress:
Stress is an abstract representation of the difficulties that threaten
to take someone out of a conflict. In a physical fight, stress can be
minor cuts, bruises, fatigue, and the like. In a social or mental
conflict, it might be loss of willpower, composure, or emotional
control...
As attacks inflict stress (which result in consequences), and blocks inhibit stress by increasing defense (resulting in less consequences), the only actual result of removing stress is to extend the conflict. This is the balancing effect to keep in mind. If one side has the ability to remove stress, and extend their staying power in the conflict, and the other one doesn't, you tip the balance in the favor of the side that can remove stress, though the fact that this is a transference in the case of non-rotes does mitigate this concern some.
With that caveat in mind, the first place one could look for an example of what could be done with removing in-combat stress is the FATE SRD. In the FATE SRD (based on Spirit of the Century), there is a skill, Science, which has a stunt Medical Attention [Science].
When using Science as first aid in the middle of a fight, the
character must take a full action with a target who’s not trying to do
anything else active (i.e., forfeiting his next action). Make a roll
against a target of Mediocre; if it succeeds with at least one shift,
the subject may remove a checkmark in his one-stress box on his
physical stress track. Every two shifts beyond the first improves this
effect by one; for example, with five shifts, a character can remove a
checkmark in his target’s three-stress box. Success can also be used
to “stabilize” someone who has taken a severe or lesser consequence
that would appear to be life-threatening (e.g., a Bleeding to Death
aspect) – in game terms, this has the effect of limiting the extent to
which the aspect can be compelled. A given person can’t be the target
of more than one first aid action in an exchange.
Under this approach, one would use an Evocation with the spell's intensity against the target of Mediocre and follow the same guidelines.
Another approach one could use is to look at stress as taken as an intensity of the blow, especially since each dot of stress is an increasing value, and the lower levels of stress won't help with higher intensity wounds. So if your Biomancer wanted to give someone the ability to clear their 4 stress box, they would require an effect with a 4 intensity. Knowing that, you can craft an evocation spell against that intensity.
Note that for balance's sake, and because this isn't explicitly laid out in the rules, the intensity might have to be altered, especially given that a moderate consequence removes 4 stress from the hit, and a mild removes 2, so the equivalency might be a bit different. But I think that these general guidelines would fit the spirit of the rules.
Best Answer
They give a very good impression of the setting, and they also give a pretty good background for understanding how the rules work.
The game was designed to very closely emulate the fiction of the books (Evil Hat and the author worked closely together for about a decade, and much of Evil Hat's work on developing and refining Fate over the years and multiple products has been intended to get "good enough" to do the Dresdenverse justice), and knowing the fiction will help understand much of the game design, especially the magic subsystem and the overall "feel" that the game's rules engender.
Another point in favour of reading the fiction is that the rules as presented are not exhaustive – the rules give you lots of leeway to come up with your own character templates, creatures, rituals, and the like. Having read the books will give you more of a grip on the world so that you can more easily make stuff that enhances the game.
I would say that reading one or more of the novels is strongly recommended, but not strictly necessary. You can still enjoy DFRPG a lot without knowing the books, and the rules do come with a lot of embedded flavour (especially if you also have Our World), so you can absorb sufficient fiction from the rule books alone.
That said, if you are getting the RPG in order to pick apart and understand Fate, it's not necessary to read the fiction. DFRPG is an excellent instantiation of Fate, and as I understand it, is the closest incarnation to the next generic version of Fate in Fate Core. However, even then you'll understand the raison d'être of much of the rules better if you know at least something of the fiction it is inspired by and attempting to support.